-int git_filebuf_open(git_filebuf *lock, const char *path, int flags);
-int git_filebuf_commit(git_filebuf *lock, mode_t mode);
-int git_filebuf_commit_at(git_filebuf *lock, const char *path, mode_t mode);
+int git_filebuf_open(git_filebuf *lock, const char *path, int flags, mode_t mode);
+int git_filebuf_open_withsize(git_filebuf *file, const char *path, int flags, mode_t mode, size_t size);
+int git_filebuf_commit(git_filebuf *lock);
+int git_filebuf_commit_at(git_filebuf *lock, const char *path);